There is provided a drinking level detecting system and a drinking level detecting method capable of improving the detection accuracy of the drinking level by allowing a third person to correct the drinking level of a driver. In a system or method which detects the drinking level of a driver of a vehicle, the drinking level of the driver is detected by an alcohol detector or the like, and the detection result is corrected by a third person other than the driver when there is an error in the detection result. Accordingly, even when the drinking level detected by the alcohol detector or the like is incorrect, the drinking level can be corrected after ensuring reliability by the determination by the third person.